US 12,476,568 B2Granted

Drive circuit for a brushless motor

AssigneeDyson Technologies Limited

InventorsStephen Greetham, Maté Horvát

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Abstract

A drive circuit for a brushless motor is described. The drive circuit includes a converter for connection to a phase winding of the motor, and a controller. The converter includes a plurality of switches and the controller controls the states of the switches to configure the converter in one of a plurality of configurations. In a first configuration, current is permitted to flow through the phase winding in a first direction and in a second opposite direction. In a second configuration, current is permitted to flow through the phase winding in the first direction and is prevented from flowing through the phase winding in the second direction. The controller includes an input for receiving a signal indicative of current in the converter, and the controller configures the converter from the first configuration to the second configuration in response to a characteristic of the current.

Claims19

Dependent claims

A drive circuit for a brushless motor, the drive circuit comprising:

a converter for connection to a phase winding of the motor, the converter comprising a plurality of switches;
and
a controller for controlling the switches to configure the converter in a plurality of configurations comprising:
a first configuration in which the converter is controlled to permit current flow through the phase winding in a first direction and in a second opposite direction;
and
a second configuration in which the converter is controlled to permit current flow through the phase winding in the first direction and is prevented from flowing through the phase winding in the second direction,
wherein the controller comprises an input for receiving a signal indicative of current in the converter, and the controller configures the converter from the first configuration to the second configuration in response to a characteristic of the current;
and
wherein each of the switches has four states:
(i) ON in which the switch is conductive in both a first direction and a second direction, (ii) D1 in which the switch is conductive in the first direction and non-conductive in the second direction, (iii) D2 in which the switch is non-conductive in the first direction and conductive in the second direction, and (iv) OFF in which the switch is non-conductive in both the first direction and the second direction;
in the first configuration, the states of a pair of switches are controlled to the ON state and the states of another pair of switches are controlled to the OFF state;
and
in the second configuration, the states of a pair of switches are controlled to one of the D1 and D2 states, and the states of another pair of switches are controlled to the OFF state.

10 more elements

A drive circuit for a brushless motor, the drive circuit comprising:

a converter for connection to a phase winding of the motor, wherein the converter comprises a plurality of legs, each leg comprises a high-side switch and a low-side switch, and each switch comprises four states corresponding to:
(i) ON in which the switch is conductive in both a first direction and a second direction, (ii) D1 in which the switch is conductive in the first direction and non-conductive in the second direction, (iii) D2 in which the switch is non-conductive in the first direction and conductive in the second direction, and (iv) OFF in which the switch is non-conductive in both the first direction and the second direction;
and
a controller for controlling the states of the switches to configure the converter in a plurality of configurations comprising:
a first configuration in which the high-side switch of a first leg and the low-side switch of a second leg are configured to the ON state, and the low-side switch of the first leg and the high-side switch of the second leg are configured to the OFF state;
and
a second configuration in which (i) the high-side switch of the first leg and the low-side switch of the second leg are configured to one of D1 and D2, and the the low-side switch of the first leg and the high-side switch of the second leg are configured to the OFF state, or (ii) the high-side switch of the first leg and the low-side switch of the second leg are configured to the OFF state, and the low-side switch of the first leg and the high-side switch of the second leg are configured to the other of D1 and D2,
wherein the controller configures the converter to the first configuration and subsequently configures the converter from the first configuration to the second configuration.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/038,184Filed 15 Nov 2021
Priority: GB 20190893 Dec 2020
Published: US 2023/0421085 A128 Dec 2023
Granted: 18 Nov 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H02P 6/06
Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position;…:…
H02P 27/04
Arrangements or methods for the control of AC motors characterised by the kind of supply voltage: using variable-frequency supply voltage, e.g.…
H02M 5/2932
Using semiconductor devices only: with automatic control of output voltage, current or power
H02P 6/085
Arrangements for controlling the speed or torque of a single motor: in a bridge configuration